<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>

<body>
  <script>
    // 算数运算符  + - * /  %  ()
    console.log(88 + 2) //90
    console.log(12 % 5) //2  
    // js 的浮点数计算精度丢失
    console.log(0.1 + 0.2)
    console.log((0.1 + 0.2).toFixed(2))

  </script>
</body>

</html>